The present invention relates to aircraft landing lights. More particularly, it refers to a sealed beam halogen light having a tulip shaped glass housing at each end of a filament envelope structure.
Commercial aircraft customarily have at least one halogen landing light on each wing. These lights have at least 600,000 beam candlepower and employ 28 volts. A-typical prior art bulb sold by SYLVANIA, Model Q4559 is shown in FIG. 1. In vibration testing indicative of air landings, such prior art bulbs tend to fail at 100 HZ and 5 G""s stage of the test. Although ANSI specification require 100 hours constant beam for aircraft landing lights this is of academic interest since vibration in the field determines the life of an aviation landing lamp. An aviation landing lamp is needed that will withstand vibrations from a greater number of repeated landings without causing lamp failure.
We have developed an aircraft landing lamp that has increased durability and vibration resistance so that it will withstand a greater number of aircraft landings without causing failure.
The lamp of this invention has an improved bulb over the prior art aviation lamps. The inventive bulb has a sealed glass envelope containing a halogen gas, a tungsten filament bonded to a metal foil material at each side of the filament and a lead wire protruding from the foil outwardly through the glass envelope. The glass envelope has a tulip shaped integral end portion at a first and second end which is enclosed at both ends with a brass end cap. A wire conductor is soldered to the protruding lead wire within each end cap. A pair of spring tempered stainless steel support posts enclose the wire conductors and each attach through a sealed lamp reflector housing enclosing the bulb to a ferrule.